7 Best Solar Charge Controllers and How to Simply Select the Right One for You

Feature Solar controller

Whether you’re going off-grid completely, supplementing your energy requirements with a grid-tie system, powering your RV, or setting up a small system to charge lights and phones… You need to find the best Solar Charge Controllers for your setup, to ensure that you protect your batteries and get the most out of your system.

A solar charge controller is a device that sits between your solar panels (solar array or photovoltaic (PV) array) and your battery bank. It regulates the current between the panels and the batteries to prevent over-charging and over-discharging, which can damage the batteries and reduce their lifespan.

As one of the most expensive, and sensitive, components in your solar setup, protecting your batteries is essential. A good solar charge controller will also prevent damage from sudden, unexpected voltage spikes and prevent reverse polarity draw from the batteries when the sun goes down.

There are hundreds of solar charge controllers to choose from and they vary widely in price, features, quality and specifications.

If you’re wondering how to select a solar charge controller – we have you covered! We researched a variety of the best solar charge controllers on the market and made this list to make it simple to select the best one for you:

7 Best Solar Charge Controllers 

No. Name Type Battery Voltage Maximum Input Maximum Output
1 Renogy Wanderer 30 Amp Solar Charge Controller PWM 12 – 24 V 50 V 30 A
2 Victron SmartSolar 20 Amp Solar Charge Controller MPPT 12 – 48 V 100 V

 

20 A

 

3 Outback Flexmax 80 Amp Solar Charge Controller MPPT 12 – 48 V 150 V 80 A
4 Epever 20 Amp Solar Charge Controller MPPT 12 – 24 V

 

100 V 20 A

 

5 Renogy Adventurer 30 Amp Solar Charge Controller PWM 12 – 24 V

 

50 V

 

30 A

 

6 Allpowers 20 Amp Solar Charge Controller PWM 12 -24 V 50 V

 

20 A
7 Renogy Rover 30 Amp Solar Charge Controller MPPT 12 – 24 V 100 V

 

30 A

Types of Solar Charge Controller – Pulse Width Modulation (PWM) Vs. Maximum Power Point Tracking (MPPT)

Broadly, there are two types of solar charge controllerPulse Width Modulation (PWM) and Maximum Power Point Tracking (MPPT). They’re both great options for the right solar set-up but they differ vastly in price and capability, so choosing the right type for your set-up is important.

Pulse Width Modulation (PWM)

These controllers offer simple and reliable technology, designed to regulate the charge going to the batteries. They do this by switching or pulsing on and off to allow charge through. The pulse duration and frequency will vary depending on the battery’s needs and the load being drawn from the battery.

They operate at a stable voltage and must be capable of handling a solar array voltage that is equal to the battery voltage, as they cannot compensate for a disparity between the two. They work best in smaller applications and where weather conditions are relatively stable.

Maximum Power Point Tracking (MPPT)

These controllers are designed to utilize the maximum power that a solar array can produce, with as little loss as possible. They can adjust for fluctuating outputs from the solar panels due to temperature and light availability and resistance from wiring etc. and maximize the performance of the panels by constantly monitoring the panels and adjusting how much it draws from them to compensate for any decrease in performance. They are a newer and more sophisticated technology, which costs significantly more than their PWM counterparts.

Check out this quick comparison between PWM and MPPT Charge Controllers by Will Prowse on YouTube:

How to Select the Best Solar Charge Controller 

There are several factors to consider when selecting the best solar charge controller for your particular set-up and its requirements:

Load or Device Size

Load refers to the combined energy requirements of all the devices/appliances your solar power set-up will be supplying with electricity.

Calculating the load involves a bit of maths (read how to calculate your solar load here) but is it essential to have that information when considering which type of solar charge controller you need and the specifications of the device you choose.

Note: very small arrays, designed to trickle charge from a 1 to 5-watt panel at less than 2 watts for each 50-battery amp-hours will not need a solar charge controller.

In the simplest of terms, a Pulse Width Modulation (PWM) solar charge controller is suitable for smaller, simple, loads and a Maximum Power Point Tracking (MPPT) solar charge controller is better for larger loads or more complex load requirements.

In addition to the load requirements, you need to consider the following:

Weather Conditions

Solar panels produce the most energy on a clear, cloudless day with bright sunlight. However, like most electronics, they perform better in cooler temperatures. The standard testing condition (STC) temperature for solar panels is 25 C / 77 F and their performance will improve as temperatures fall below that or decline as temperatures rise above that.

However, cooler temperatures often go hand in hand with clouds and rain, which will negatively impact performance and hotter temperatures often go hand in hand with long, hot, summer days where there are more hours of daylight.

As such, the weather conditions will affect the performance of your solar array in slightly more complex ways than just temperature and light availability.

PWM solar charge controllers work well in conditions where the weather is stable and consistent. They do not compensate for temperature and if the temperature is high and the input voltage to the controller drops, they will not compensate for this. This means the input voltage may drop below the threshold and prevent the batteries from charging properly.

MPPT solar charge controllers are more sophisticated and better suited to areas where the weather changes frequently and both temperature and light availability are more varied. They can adjust for temperature variations and maintain a steady input voltage to the controller. This can result in improved performance and result in gains of up to 30% in power, despite the drop in panel performance.

Voltage

Your solar charge controller must be able to release the correct voltage for the battery bank – usually 12, 24 or 48 Volts. This is the controller’s maximum output voltage. If the controller releases more volts than the batteries can handle, it will damage the batteries. If it releases too few volts for the batteries, they won’t charge effectively.

More importantly, your solar charge controller must be able to handle the maximum voltage that the solar panels / solar array can produce. This is the controller’s maximum input voltage.

To calculate the maximum input voltage, you need to work out the maximum output of the solar array. On a single panel, this is called the ‘short circuit current’ and will be labeled as ‘Isc’ on the panel’s specifications. If you are using several panels in parallel or in series, you will need to calculate the combined maximum output:

  • Parallel: for solar panels wired in parallel, the amperage (current) is additive, but the voltage remains the same (e.g. 4 x 12 volt /5-amp solar panels = 12 volts/20 amps).
  • Series: for solar panels wired in series, the voltage is additive, but the amperage remains the same (e.g. 4 x 12 volt /5-amp solar panels = 48 volts/5 amps).

An increased safety factor of 25% should be factored in, to protect against unforeseen events where the solar panels produce more power than they are rated for. Things like light reflected off snow combined with cold temperatures and a clear, sunny sky could boost the performance of the solar panels significantly so the charge controller must be able to handle that.

Where a PWM controller is used, the solar array voltage and the battery voltage must be the same.

MPPT controllers can work well where the array voltage is higher than the battery voltage.

Where it Will be Situated 

The distance between the solar panels and the battery bank will impact the performance of the system due to ‘voltage drop’ as the charge travels along the wire from the panels to the charge controller and the batteries.

The longer the distance, the more significant the losses will be. This can be calculated and compensated for by using a thicker gauge wire or reducing the distance.

However, wiring is expensive and moving your panels may not be viable, so if your losses will be significant it is best to invest in an MPPT solar charge controller because it will compensate for the reduction in voltage.

Safety and Monitoring Features

Different solar charge controllers come with a wide range of extra features that make them easier to use and provide important safety features to prevent over-charging, over-discharging, overload, short-circuits, reverse polarity and electric arcs.

They also provide features for data logging and system monitoring, either on the device or remotely via Bluetooth, as well as system management options that can be managed remotely.

Selection Criteria 

We have selected 7 of the best solar charge controllers on the market for you to compare and choose from, based on your specific needs and conditions. Our selection is based on the selection criteria discussed above, namely:

  • Type
  • Battery Voltage and Compatibility
  • Maximum Input
  • Maximum Output
  • Extra Features and Safety Measures

7 Best Solar Charge Controllers   

 

1. Renogy Wanderer 30 Amp PWM

Renogy Wanderer Solar Charge Controller

Type: Pulse Width Modulation (PWM)

Battery Voltage and Compatibility: Optimized for a 12

V/24V system and compatible with Deep Cycle Sealed (AGM), Gel, Flooded and Lithium batteries.

Maximum Input: 50 V

Maximum Output: 30 A

Extra Features and Safety Measures:

  • Integrated RS232 port allows communication with the BT-1 Bluetooth module and usage of Renogy BT smartphone app.
  • Integrated 5V 2A USB ports to charge USB devices.
  • Safety features for reverse polarity, overcharging, short-circuit, and reverse current.
  • Temperature sensor.
  • Backlit LCD screen display

Price it on Amazon: Renogy Wanderer 30 Amp PWM 

What the Amazon Reviews Say (4.3/5):

Pros:

  • Very affordable
  • Easy to install
  • Reliable and respected brand
  • Simple to set up

Cons:

  • Poor after purchase support
  • Vague/unclear instructions in the user manual
  • Small connection ports

2. Victron SmartSolar 20 Amp MPPT 

Victron SmartSolar Charge Controller

Type: Maximum Power Point Tracking (MPPT)

Battery Voltage and Compatibility: 12, 24 and 48 Volts. Compatible with Deep Cycle Sealed (AGM), Gel, OPzS, OPzV, Lithium-ion, traction batteries and more.

Maximum Input: 100 V

Maximum Output: 20 A

Extra Features and Safety Measures:  

  • Remote control and monitoring via Bluetooth and VictronConnect
  • Intelligent Load Output function prevents damage caused over draining batteries. Parameters can be set manually so that batteries are not drained below the specified charge level.
  • Internal temperature sensor
  • Output short circuit / overheating

Price it on Amazon: Victron SmartSolar 20 Amp MPPT

What the Amazon Reviews Say (4.7/5):

Pros:

  • Easy to install
  • Compact and sturdy fabrication
  • Efficient at charging and utilizes more power from the solar panels
  • Bluetooth for monitoring and regulating

Cons:

  • No screen – Bluetooth to separate device only
  • Bluetooth was inconsistent on Android and range was poor
  • Ports are on the small side (difficulty with 10-gauge wire)

3. Outback Flexmax 80 Amp MPPT

Outback Flexmax Solar Charge Controller

Type: Maximum Power Point Tracking (MPPT)

Battery Voltage and Compatibility: 12, 24, 36 and 48 Volts. Programmable to Charge Battery Voltages from 12 VDC to 60 VDC. Compatible with a variety of batteries including all wet cell/AGM batteries and lithium-ion batteries.

Maximum Input: 150 V

Maximum Output: 80 amps

Extra Features and Safety Measures: 

  • Active cooling and intelligent thermal management cooling for operation at up to 40C/104F.
  • A built-in, backlit 80-character display
  • Shows the current status and logged system performance data for the last 128 days.
  • Can be remotely programmed and monitored via a MATE system display and provides unrivalled complete system integration.

Price it on Amazon: Outback Flexmax 80 Amp MPPT

What the Amazon Reviews Say (4.7/5):

Pros:

  • Easy to install
  • Extensive manuals available online
  • Gives good power from panels on a cloudy day

Cons:

  • The screen is small and not easy to read and buttons are small you need something to press them if your hands are big
  • The fan may be loud and it clicks when it turns on (not ideal for close proximity areas like an RV)
  • Customer support was poor

4. Epever 20 Amp MPPT

Epever MPPT

Type: Maximum Power Point Tracking (MPPT)

Battery Voltage and Compatibility: 12 and 24 Volts. Compatible with Sealed, GEL, AGM and Flooded, Lithium (LiFePO4)

Maximum Input: 100 V

Maximum Output: 20 amps

Extra Features and Safety Measures: 

  • Compatible with Epever Tracer-A/AN/BN, LS-B/BP, VS-BN series controllers
  • Automatic identifies relevant parameter data for the batteries connected to
  • Large-screen multifunction LCD shows all the operational data and system working status
  • Real-time energy statistics recording
  • Longer communication distance based on RS485
  • Diversified load control modes: manual, light ON/OFF, Light ON+ Timer, Time Control

Price it on Amazon: Epever 20 Amp MPPT 

What the Amazon Reviews Say (4.7/5):

Pros:

  • Well made, sturdy unit
  • Easy to install and set up
  • Remote screen (connected) to monitor performance

Cons:

  • The cable for the screen is too short
  • Software for remote monitoring on PC is difficult to install
  • Some reviewers had problems with the warranty over technicalities that aren’t covered

5. Renogy Adventurer 30 Amp PWM

Renogy Adventurer Solar Charge Controller

Type: Pulse Width Modulation (PWM)

Battery Voltage and Compatibility: 12 and 24 Volts. Compatible with Deep Cycle Sealed, Gel, Flooded and Lithium Batteries.

Maximum Input: 50 volts

Maximum Output: 30 amps

Extra Features and Safety Measures:  

  • Smart 4 Stage PWM charging and temperature compensation.
  • Protective features for reverse polarity, overcharging, short-circuit and reverse current.
  • Backlit LCD screen for displaying operating information and error codes.
  • The USB port on the front display can be used to charge mobile phones, tablets, speakers, etc.
  • RS232 port allows communication with the BT-1 Bluetooth module and usage of Renogy BT smartphone app.

Price it on Amazon: Renogy Adventurer 30 Amp PWM

What the Amazon Reviews Say (4.3/5):

Pros:

  • Flush wall mounting or surface mounting
  • Terminal ports are sturdy and can take 10-gauge wire easily
  • LCD display works well and it can also be connected to a separate Bluetooth monitor

Cons:

  • Software problems on IOS
  • Terminal ports are awkwardly positioned and it needs to be unmounted to disconnect a cable
  • The temperature sensor is ignored in Lithium mode

6. Allpowers 20 Amp PWM

Allpowers 12 v Solar Charge Controller

Type: Pulse Width Modulation (PWM)

Battery Voltage and Compatibility: 12 to 24 volts. Compatible with sealed lead-acid, gel, flooded and Lithium-Ion (LIFePO4)

Maximum Input: 50 volts

Maximum Output: 20 amps

Extra Features and Safety Measures: 

  • Protective features: Over-current and short-circuit protection, inverse connection protection, low voltage and overcharge protection
  • Comes with a display screen and indicates the status and data. Modes and parameter configuration can be adjusted by the user.
  • Industrial-grade STM 8 microprocessor to control the charge and discharge processes.

Price it on Amazon: Allpowers 20 Amp PWM 

What the Amazon Reviews Say (4.2/5):

Pros:

  • Customizable parameters
  • Dusk ‘til Dawn feature allows you to program loads to turn lights on/off etc.
  • Two USB ports for charging devices like phones

Cons:

  • The user manual is not very clear on how to program the unit
  • Connectors are on the small side (difficulty connecting 10-gauge wires)
  • Unit is not waterproof

7. Renogy Rover 30 Amp MPPT

Renogy Rover MPPT

Type: Pulse Width Modulation (PWM)

Battery Voltage and Compatibility: 12 and 24 volts. Compatible with Deep Cycle Sealed, Gel, Flooded, and Lithium (12.8V LFP).

Maximum Input: 100 V

Maximum Output: 30 amps

Extra Features and Safety Measures:

  • Positive Ground controller
  • 4-stage charging and temperature compensation.
  • Protective features for reverse polarity, overcharging, over-discharging, overload, short-circuiting, and reverse current.
  • LCD screen and multiple LED indicators for displaying system operation information and error codes.
  • Customizable parameters.
  • Aluminum heat sink allows for efficient heat dissipation.
  • RS232 port allows the Rover PG to communicate with the BT-1 Bluetooth module, which can pair with the Renogy BT smartphone app.

Price it on Amazon: Renogy Rover 30 Amp MPPT

What the Amazon Reviews Say (4.4/5):

Pros:

  • Optional Bluetooth adaptor for connecting to a smartphone or device
  • Fully customizable parameters
  • Provides detailed information for system monitoring

Cons:

  • Complicated to set up and the manual is not very clear
  • Software for IOS and PC not very user-friendly/difficult to set up
  • Poor customer service

Best Solar Charge Controllers – Our Two Top Picks

As you can see, Solar Charge Controllers come in a wide range of specifications to meet an even wider number of solar setup requirements. Of the 7 we reviewed above; we have chosen two as our top picks. These are the ones that we believe offer the best value for money and the most in terms of functions and extra features:

Top Pick (MPPT Type): Victron SmartSolar 20 Amp MPPT

Our top pick MPPT type solar charge controller is the Victron SmartSolar MPPT 100/20. This one stands out for several reasons and is very moderately priced in comparison to other MPPT charge controllers.

Aside from the great price point, it is made by Victron Energy in the Netherlands, who have a reputation for their excellent quality.  It is equipped with an intelligent system, which is fast and user friendly, even for inexperienced users.

The built-in Bluetooth management system allows you to monitor the system and make any adjustments remotely from a smartphone or compatible device via VictronConnect. Remote management is also accessible via the Victron Remote Management Portal over the internet or through an optional extra Bluetooth device connected via a long-range wide area network (LoRaWAN), for when there is no connectivity in the area.

It is configured for a three-step charging process and can be programmed for equalization on lead batteries. The device itself is equipped with LED indicator lights that give you a real-time indication of which charging stage active and alerts you to and diagnoses system faults.

As an MPPT solar charge controller, it can maximize the efficiency and performance of your solar array and can yield up to 30% more power than non-MPPT controllers. It is suitable for medium to large systems and will work well in locations with variable weather conditions.

These features combined with the great price make it our favorite MPPT solar charge controller for a wide ‘array’ of solar setups.

Top Pick (PWM Type): Renogy Wanderer 30 Amp PWM

Our top pick PWM type solar charge controller is the Renogy Wanderer. As one of the least expensive options, this small device comes packed with value for money. It is made by the well-respected Renogy brand and it is a great option for completely off-grid setups.

The Renogy Wanderer comes pre-programmed with the parameters for different battery types (including Lithium, AGM, gel or flooded batteries). It utilizes an efficient 4-stage (Bulk, Boost, Float, and Equalization) charging process. Every 28 days, the Equalization stage for AGM and flooded batteries will ‘overcharge’ the batteries for a controlled period, which is beneficial to them.

It also features self-diagnostics for system faults and provides protection features for overcharging, overcurrent, short circuit, reverse current and reverse polarity. These features provide an added layer of protection to your system and your batteries, beyond the benefits of having accurately regulated charge control.

The unit comes with a backlit LCD screen to display operational information, diverse load control, and error codes for diagnostics. It also features an RS232 port for communication with Bluetooth T-1 module (separate purchase) and two USB (5V/2A) ports for convenient charging to devices.

Considering these great features and the incredibly low price… The Renogy Wanderer is definitely, in our opinion, the best solar charge controller in the PWM category!

References & Useful Resources:

Clean Energy Reviews – The Best Solar Battery Systems 

DSIRE – Database of State Incentives for Renewables & Efficiency

Science Direct – Temperature Dependent Photovoltaic (PV) Efficiency and Its Effect on PV Production in the World

Unbound Solar – How to Size a Solar System

Unbound Solar – Voltage Drop Calculator For Solar Electric Systems

Frequently Asked Questions

What is a solar charge controller?

A solar charge controller is a device that sits between your solar panels (solar array or photovoltaic (PV) array) and your battery bank. It regulates the current between the panels and the batteries to prevent over-charging and over-discharging, which can damage the batteries and reduce their lifespan. As one of the most expensive, and sensitive, components in your solar setup, protecting your batteries is essential

Is MPPT better than PWM?

It depends on your setup and your location / climate. MPPT Solar Charge Controllers are more sophisticated and can maximize solar panel performance and do better in challenging weather conditions but they are also much more expensive than PWM Solar Charge Controllers, which do a great job on smaller setups or setups in more stable weather conditions.

How to select a Solar Charge Controller?

To select the best Solar Charge Controller for your system you need to consider the type of controller (MPPT vs PWM), compatibility with your battery type and voltage, the maximum input voltage from your solar panels and the maximum output amps you need to power your load, as well as extra features and protective safety features.

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